GM Service Manual Online
For 1990-2009 cars only

Diagnostic Aids

Hard shifting can be diagnosed easily. You should also perform a static shift and a dynamic shift test. Many simple factors could occur such as excessive clutch pedal free travel, insufficient fluid, excessive fluid or even the wrong transmission lubricant. A misaligned transmission can also cause hard shifting as well as a worn or defective clutch, binding of the shift control. Many internal components can also play a factor in hard shifting such as the front bearing retainer loose or cracked, synchronizer worn, damaged or improperly assembled. A failure to fully depress the clutch pedal when shifting will cause hard shifting.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. This step checks for a faulty shift control.

  2. This step checks for a faulty or worn clutch pressure plate or clutch driven plate.

Step

Action

Yes

No

DEFINITION: The transmission does not shift smoothly or without difficulty into another gear.

1

Did you review the manual transmission symptom operations and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Manual Transmission

2

Inspect for proper clutch operation. Refer to Hydraulic Clutch Description in Clutch.

Did you find and repair the condition?

Go to Step 11

Go to Step 3

3

Inspect the transmission shift control for binding.

Did you find and repair the condition?

Go to Step 11

Go to Step 4

4

Replace the transmission shift tower. Refer to Shift Tower Replacement .

Did you find and repair the condition?

Go to Step 11

Go to Step 5

5

Inspect the transmission for the correct type transmission fluid.

Is the correct type fluid being used?

Go to Step 7

Go to Step 6

6

Drain and refill the transmission with the correct type fluid.

Does the transmission still shift hard?

Go to Step 7

Go to Step 11

7

Inspect the clutch pressure pate and/or clutch driven plate.

Is the clutch pressure plate and/or clutch driven plate worn or faulty?

Go to Step 8

Go to Step 9

8

Replace the clutch pressure plate and/or clutch driven plate. Refer to Clutch Assembly Replacement in Clutch.

Did you find and repair the condition?

Go to Step 11

Go to Step 9

9

Remove the transmission. Refer to Transmission Replacement .

Inspect the transmission for an internal bind, possibly caused by one of the following:

    • Shift forks
    • Selector plates
    • Synchronizers

Is there an internal bind?

Go to Step 10

--

10

  1. Replace worn or damaged components as necessary. Refer to Transmission/Transaxle/Transfer Case Unit Repair Manual.
  2. Install the transmission. Refer to Transmission Replacement .
  3. Operate the system in order to verify the repair.

Did you find and repair the condition?

Go to Step 11

Go to Diagnostic Aids

11

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 1